The present invention relates to closures such as those commonly employed on flexible storage bags, particularly those suitable for use in the containment and protection of various items including perishable materials.
Flexible storage bags for use in the containment and protection of various items, as well as the preservation of perishable materials such as food items, are well known in the art. Such bags typically comprise a rectangular sheet of polymeric film folded upon itself and sealed along two edges to form a semi-enclosed container having two flexible opposed sidewalls, three sealed or folded edges, and one open edge. A closure integrally formed with the bag such as an interlocking rib-type seal or separately provided such as a plastic or paper-clad-wire tie completes the containment assembly.
As utilized herein, the term xe2x80x9cflexiblexe2x80x9d is utilized to refer to materials which are capable of being flexed or bent, especially repeatedly, such that they are pliant and yieldable in response to externally applied forces. Accordingly, xe2x80x9cflexiblexe2x80x9d is substantially opposite in meaning to the terms inflexible, rigid, or unyielding. Materials and structures which are flexible, therefore, may be altered in shape and structure to accommodate external forces and to conform to the shape of objects brought into contact with them without losing their integrity. Flexible storage bags of the foregoing variety are typically formed from polymeric film, such as polyethylene or other members of the polyolefin family, in thicknesses of between about 0.0002 inches to about 0.002 inches. Such films are frequently transparent but sometimes are opaque and/or colored.
Flexible storage bags of the currently commercially available variety provide a means of conveniently storing a wide range of objects and materials in a generally disposable containment device. Many commercially available flexible storage bags utilize mechanical interlocking seals to achieve closure of the bag opening, and some such bags additionally employ a sliding mechanical closure to improve the ease of opening and closing mechanical interlocking seals. With either type of mechanical interlocking seal, there remains the issue of determining whether complete closure has in fact been completed across the mouth of the bag to achieve the desired completion of the closing operation.
Accordingly, it would be desirable to provide a closure which provides for a positive indication of when a complete closure has been achieved.
The present invention provides a flexible storage bag having an opening, a closure system for the opening, and a closure indicator. The closure may comprise interlocking seals closable by a slider. The slider may cause release of encapsulated gas by rupturing pockets containing encapsulated gas. Alternatively, the closure indicator may comprise resiliently deformable protuberances. The resiliently deformable protuberances are disposed in the path of the slider, whereby the slider intercepts and resiliently deforms the protuberances upon translation. After the slider has intercepted and released the protuberances, they snap back into position producing the audible signal.
Alternatively, the closure indicator may comprise a mechanical seal having a rack disposed at least partially along the length of the mechanical seal. The slider has a resiliently mounted ratchet finger which intercepts the rack upon translation. The ratchet finger produces an audible sound in response to intercepting the individual teeth of the rack. Alternatively, the slider may comprise a pinion gear mounted on the slider which engages the rack and rotates in response to translation of the slider. The resilient ratchet finger may engage the pinion gear and produce the audible signal in response to engagement and release by the teeth of the pinion gear.
In yet another embodiment, the closure indicator may comprise materials distorted in response to being intercepted by translation of the slider and thereby produce an audible sound upon distortion.